It is common practice to marinate foodstuffs to enhance or change their flavor and to tenderize less expensive cuts of meats. Typically, meat or poultry is placed in a marinating liquid for an extended period of time so that the meat or poultry may absorb the marinating liquid and its flavor. Whereas marinating is a relatively simple process the time it takes for the foodstuff, such as meat, poultry, or vegetables to absorb sufficient quantities of marinating liquid is often a substantially long duration of time. Allowing meat, poultry and vegetables to remain in a marinade for as long as forty-eight hours prior to cooking is a common practice. As an example, Sauerbraten is typically prepared by placing beef bottom round roast, a relatively inexpensive meat, in a marinating liquid for up to 48 hours to flavor and tenderize the meat prior to its being ready for cooking. Very often time does not permit such thorough marinating and the quality and flavor is typically less than what it would have been with proper preparation.
Methods of marinating foodstuffs are well known in the art. U.S. Pat. Nos. 4,818,550 and 5,057,332 to Davidson, et al., and U.S. Pat. No. 3,928,634 to Gasbarro, disclose marinating meats and poultry by forming a vacuum (negative pressure differential) to suck the air out of the food that form spaces within the food into which the marinating liquid may enter and fill. Using vacuum techniques, for marinating of foodstuffs, however has disadvantages.
First, the greatest possible vacuum that can be achieved results in a pressure differential of one atmosphere--i.e., 14.7 pounds per square inch. To achieve this 14.7 psi pressure differential the vacuum and the vacuum seal must be perfect. As a perfect vacuum is unachievable, and defects in the vacuum seal decrease the ability to maintain the pressure differential, the actual difference in pressure may be significantly less than this greatest possible value.
Secondly, atmospheric pressure varies with altitude, and accordingly the greatest possible pressure differential that may be achieved also varies. For example, at sea level, the greatest possible pressure differential achievable is 14.7 psi, whereas, at an altitude of 5000 feet, the greatest possible difference in pressure differential may only be 12 psi; a 20% reduction in pressure.
Third, the level of absorption of the marinating liquid into the foodstuff is limited by the pressure differential achieved. As the marinating liquids begins to fill the spaces that are evacuated of air, the liquid filling the spaces in the outer food layer prevents entrapped air from escaping from the center layers of the food. The air thus remains trapped in the center of the food and either greater pressure differentials or longer periods of marinating are necessary to extract this trapped air and thoroughly marinate the foodstuff.
Other methods, using positive pressure to infuse liquids into foodstuffs, are known in the art. These methods, however, are more concerned with preservation of food rather than marinating to enhance flavor. U.S. Pat. No. 194,550 to Echart, U.S. Pat. No. 474,446 to Fey, U.S. Pat. No. 550,151 to Averkamp, and U.S. Pat. No. 1,052862 to Trescott disclose methods of using very high pressure over long periods of time to pickle meats and fish for preservation.
It would thus be highly desirable to reduce the time required to thoroughly marinate foodstuffs. The apparatus and method disclosed herein not only thoroughly marinates foodstuffs in a fraction of the time typically required for the marinating process, but also provides for greater penetration of the marinating liquid into the foodstuffs.